Physics, 28.01.2020 02:31 Queenhagar

An 80-kg rock climber is standing on a cliff so that his gravitational pe =10,000 j. what percent increase in height is required to raise his pe by 3500 j

Answers: 1

Show answers

Answers

Answer from: zmerriweather167

35.2 %

Explanation:

The initial PE of the climber is given by

PE=mgh

where

PE = 10,000 J

m = 80 kg is the mass

g = 9.8 m/s^2 is the gravitational acceleration

h = ? is the initial heigth of the climber

Re-arranging the equation, we can find h:

$h=\frac{PE}{mg}=\frac{10,000 J}{(80 kg)(9.8 m/s^2)}=12.8 m$

Now we are told that the PE raises by 3500 J, so we have:

$\Delta PE = mg \Delta h=3500 J$

where $\Delta h$ is the increase in height. Solving for this variable, we find

$\Delta h =\frac{\Delta PE}{mg}=\frac{3500 J}{(80 kg)(9.8 m/s^2)}=4.5 m$

and so, the percent increase in height is

$\frac{\Delta h}{h} \cdot 100 = \frac{4.5 m}{12.8 m}\cdot 100=35.2\%$

Answer from: elijaahstepp041

The answer is:

35 %

Let us solve first the height the rock climber is at, if the gravitational PE=10,000J.

Gravitational PE is the potential energy of an object relative to its position. You can use the formula:

PEgrav = mgh

Where:

PEgrav = gravitational PE

m is mass

g is acceleration due to gravity = 9.8m/s² (this is constant on Earth)

h is height

There is an easy way to do this.

Based on the equation, we know that PEgrav is directly proportional to h. So a percentage increase in height would be equal to the percentage increase in PEgrav and vis-a-vis.

Given that, first we solve the percent increase in PEgrav, by determining what percent is 3,500J of 10,000J.

$\dfrac{3,500J}{10,000J}x100=35$

So if there is a 35% increase in PEgrav height, then we can assume that there was a 35% increase in height.

Let's take your problem and solve it the longer way:

Given:

m = 80kg

g = 9.8m/s²

h = ?

PEgrav = 10,000 J

PEgrav = mgh

$10,000J = (80Kg)(9.8m/s^{2})(h)$

$10,000J=(784Kg*m/s^{2})(h)$

$\dfrac{10,000J}{784kg.m/s^{2}}=h$

12.76m=h

This is the height the rock climber is at given the gravitational PE is 10,000.

Now for the next part, you need to solve for the height to get the PEgrav raised by 3,500J. So the new PEgrav would be 13,500J.

Just do the same procedure again, but instead of 10,000J you will use 13,500J.

$13,500J=(80Kg)(9.8m/s^{2})(h)$

$13,500J=(784Kg*m/s^{2})(h)$

$\dfrac{13,500J}{784kg.m/s^{2}}=h$

17.22m=h

Get the difference between the two heights:

17.22m - 12.76 = 4.46m

Find what percent is 4.46m of the original height:

$\dfrac{4.46m}{12.76} x 100=35$

Answer from: Quest

I'd go for the one that says that knees are fulcrums, lower legs are levers and the ankles hold loads.hope it ,happy homework/ study/ exam!

Answer from: Quest

Answerapplying a direct current to a non magnetic material in order to create a electromagnetic field; plz check first good luck;

Other questions on the subject: Physics

Physics, 22.06.2019 19:30, diyagawande

Complete these sentences. if a roller coaster train has a potential energy of 1,500 j and a kinetic energy of 500 j as it starts to travel downhill, its total energy isj. once the roller coaster train gets closer to the bottom of the hill, its kinetic energy increases to 1,100 j, and its potential energy decreases to j. when the train reaches the bottom of the track and is traveling along the ground, its kinetic energy isj.

Answers: 1

continue

Physics, 23.06.2019 00:00, cece3467

The horizontal blue line through the middle of the lens is called the optical axis. as the lamp is moved above or below the axis, keeping the horizontal distance to the center of the lens constant, how does the horizontal distance from the lens to the image change?

Answers: 2

continue

Physics, 23.06.2019 00:30, asiaboo37

If you let go of the notebook after lifting it, will it move? how?

Answers: 1

continue

Physics, 23.06.2019 02:00, Apple557

How did the germans define who was jewish?

Answers: 1

continue

You know the right answer?

An 80-kg rock climber is standing on a cliff so that his gravitational pe =10,000 j. what percent in...